Children's Health

Antibiotics in Infancy Linked to IBD Risk

May 5, 2010 -- Children with inflammatory bowel disease (IBD) are nearly three times more likely to have been prescribed antibiotics in the first year of life than children without IBD, researchers report.

The study is small and the findings need to be confirmed. And even then, it could be some other factor associated with antibiotic use, not the drugs themselves, that explain the link.

"Still, we are the first group in North America to find this important association," which may offer clues into the causes of IBD, says Souradet Y. Shaw, a PhD candidate at the University of Manitoba in Winnipeg. "Despite intense research on IBD, its causes remain elusive."

The motivation for the current study, Shaw tells WebMD, is recent research suggesting that imbalances in normal intestinal bacteria underlie some forms of IBD. "Infancy is the important developmental period for these bacteria, and antibiotic use can affect the development of the bacteria."

Up to 1 million Americans have inflammatory bowel disease; the main types are ulcerative colitis and Crohn's disease. The inner lining of the intestines becomes inflamed and damaged, causing abdominal pain, diarrhea (which may be bloody), weight loss, and rectal bleeding.

IBD Risk: Boys vs. Girls

Using a database of all Manitobans diagnosed with IBD, the researchers identified all 36 children age 11 and younger diagnosed with IBD in that province between 1996 and 2008.

Then, using the Drug Program Information Network, the prescription records of the 36 children with IBD were compared to those of 360 children without IBD matched by age, sex, and region of residence. Their average age was 6 1/2; about half of each group was boys.

The findings were presented at Digestive Disease Week 2010 in New Orleans.

Overall, nearly 60% of the children with IBD had received one or more prescriptions for antibiotics in the first year of life compared with about 40% of the children without IBD.

"This translated into an almost three times increased chance of developing IBD if antibiotics were used in infancy," Shaw says.

Boys with IBD were nearly seven times more likely to have been prescribed antibiotics in infancy than boys without IBD. But there appeared to be no link between IBD and antibiotic use in girls.

Study Limitations

Given the small number of children studied, "it would be irresponsible to overstate our findings," Shaw says.

Also the researchers did not look at type of antibiotics or determine whether greater use of antibiotics was associated with a greater risk of IBD, as would be expected if the association was real.

Additionally, the study doesn't show cause and effect. It could be that infants who require antibiotics may be predisposed to developing IBD for some other reason, Shaw says.

If the findings are confirmed, that does not mean that antibiotics should be withheld during infancy, says Deborah Procter, MD, a gastroenterologist at Yale University. But given the current problem of antibiotic overuse leading to resistant strains of bacteria, Potter tells WebMD they may offer one more reason to "think twice before prescribing them."

The next step is to look at whether antibiotic use in infancy with associated with higher odds of IBD in kids with a family history of the disorder, Shaw says.